Method of making retainer locks



Dec. 14, 1937.v E1 A MCBRlDE 2,102,473

METHOD OF MAKING RETAINER LOCKS Filed Oct. 8, 1936 2 SheeLS-SheeTl 2 M' ul mmm? YPatented Dec. 14.1937

Eugene A. McBride, Cleveland, Ohio, assigner to Thompson Products, Incorporated, Cleveland, Ohio, a corporationof Ohio i Y VAmunt-afim october s, 193s, serial No. 104,619

- comme. (c1. .15s-'2)v a 'This invention relates to a method of making retainer locks,y such as the "split,Y tapered collars or bushingsused in lvalveasseinblies to secure the spring retainer plates in position.y n

VIn accordance with this inventin, a metal strip or bar having substantiallythe"'desired cross Section of the iinished retainer lock issubjected 'to a series of severing and forming operations to y produce a lock ofthe desired finished dimensions.

Thev metal-strip is advanced into position between'in'ale and female forming'dies, where it is temporarily supported upon stripping members or kiek-out bars.A Upon relative `movement of the dies rtoward each other, a blank is severed from the-end--poitionofthe'stripv of ay length slightly A greater than the-finished length of the retainer lock, and this blank is bent into substantially semi-cylindrical fornithrough the further action of the dies. `Whi1e the blank is still supported between the forming dies, knives are moved in` radially of the formed blank to sever the edges thereof to the proper finished length of the collar or retainer locky member.

VBy employing the forming dies as the supporti retainer locks and similar devices, wherein a con-V tinuous metal strip is first severed and the severed portion bent into the desired form but of a length `greater than that of the finished retainer lock, and the formed blank trimmed to the final dimensions while supported between the forming surfaces themselves. Y. Y n

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

-This invention (in a preferred-form) is illustrated in the drawings and hereinafter more fully v described.

On the drawings:

Figure 1 is a fragmentary elevational view, part- Y 1y in section, of the die forming elements used in carrying out the method of this invention.V

Figure 2 is a fragmentary sectional view'taken substantially along the line II--II of Fig. 1, with parts in elevation. f Y

Figure 3 is a fragmentary plan viewof a metal .are formed.

' against the forming surface I3 of the male die strip from which the valve spring retainer'locks Figure 4 is'an' end planview of a nished valve spring retainer lock member. y c A 'Y Figure 5 is ari evatinal view of the finished 5 lockmember of 1*ig'.1r. IL Figures 6 to 9l inclusive illustrate variousY steps in the making of the valve spring retainer locks,

showing theV upper or-female' forming die `in elevation and the lower, or male forming die and associated' parts in section." As shcwnron the drawings: f 1 vThe reference numeral Ill indicates the bed plate of a suitable type of forming'` machine for Carrying out the method or thi'sinvetiongr-A die i IA is mounted in said .bed platekfor vertically reciprocating movement arid carries at itsfu'pper a male forming member I2 havingV a con-ven' forniing surface I3. Stripping members, or kick-out. bars I4 and l5 extend through the lower portion of the die II to project on each side of the male die head I2. Knives I6 and I1 are positioned in horizontal, opposed relation for movement radially-of the cylindrical forming surface I3 of said male die I2. 25

An upper die I8 is carried by a suitable holding memberv I9 for verticalv movement in alignment with the lov/er die II. Said upper die I8 is provided with a tapered concave forming surface '20 adapted to cooperate with the forming surface i3 of the lower die. f Y

In accordance with' my method, the valve spring retainer locks are formed from a continuous strip 2l (Fig. 3) of metal which has preferably been rolled or otherwise worked to provide one or more Vbeads 22 along one broad face of thek strip.` Said strip 2| is also preferably tapered in cross section to provide arsection similar to that of the nished retainerV lock. s

Asrshown in Figs. 1 and 2, the strip 2| is advanced through a s'lot 23 of conforming cross section provided in the bed plate I0, so that an end portion of said strip 2| is guided and supported upon the ends of the kick-out bars I4 and I5 above the male die I2. Said kick-out bars I4 and I5 are provided at their ends with grooves 24 for receiving the bead 22, thus insuring proper alignment of said bead 22 with the groove 25 formed in the surface I3 of the male die I2.

As the upper die I8 is lowered, it rst severs the end portion of the strip 2| to provide a blank collar. As the upper'die I8 moves'the blank 21 I2, the kick-out bars I4 and I5 are lowered clear of the work. At the same time the blank 21 is bent into substantially semi-cylindrical form between the forming surfaces I3 and 2|] of the lowei` and upper dies, respectively.

After the forming of the blank 21, and while the blank 21 is still held between the cooperating dies I2 and I8, the knives I6 and I'I are operated to move relatively toward each other radially of the semi-cylindrical blank to trim the longitudinal edges 28 and 29 thereof. To insure accuracy in this severing operation, the head I2 of the lower die is provided with sharp undershoulders 3U with which the cutting edges of said knives I6 and I1 cooperate.

After the severing operation has been completed, the upper die I8 is raised clear of the bed plate and the kick-out bars I4 and I5 are elevated to strip the finished retainer lock member, indicated by the reference numeral 3| (Fig. 9), from the lower die I2. `Suitable means (not shown) may be employed for removing the finished re-V tainer lock member from the kick-out bars I 4 and I5. Y

The operation is then repeated to form identical valve spring retainer lock members, or half collars, which are used in pairs in the usual manner for holding the valve spring retainer plate in place in valve assembly. For such purpose, it is extremely necessary that the lock members be accurately dimensioned and this is one of the advantages of the method just described.

An important feature of my method which contributes to the precision as to the dimensions of the final lock member, is the provision for the supporting of the blank between the forming surfaces of the upper and lower dies during the nal trimming operation. The formed blank has no opportunity to spring out of shape, owing to the fact that it is rmly held under considerable pressure between the faces of the dies. Consequently, the relatively heavy impact of the knives I6 and I'I in the trimming operation cannot alter the shape of the formed blank. The excess metal along the longitudinal edges of the formed blank can also be very accurately trimmed off to leave finished surfaces that need no further machining.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles -of this invention, and I, therefore', do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art. Y

I claim as my invention:

1. In the method of making valve spring retainer locks from a metal strip, the steps which comprise severing a blank from said strip of a length slightly greater than thelength of a nished lock, Vforming said blank to the shape of a finished lock between. forming dies and severing opposite edges ofsaid blank while supported between said dies to produce a lock of the desired finished dimensions.

2. The method of making collars from metal strip, which comprises guiding and supporting an end of said strip upon stripping members between male and female dies, severing a blank from said strip end of greater length than that of the finished collar, bending said blank to the desired shape between saidV dies, severing the edges of said shaped blank while held between said dies to produce a collar of finished dimensions and stripping said collar from said dies by means of said stripping members.

' EUGENE A. MCBRIDE. 

